When watching over residents and controlling devices in accordance the situation, it is necessary to monitor the state such as the positions of the residents. As a method for acquiring position information, methods using, for example, a surveillance camera, infrared image sensor, floor pressure sensor, ultrasonic sensor, and a combination of wireless tag and reader are conventionally known. When using these advanced sensors, however, the problems of privacy and cost arise.
JP-A 2008-77361(KOKAI) discloses a monitoring system for estimating the number of persons existing in each area by combining a pyroelectric sensor and person count sensor.
The monitoring system disclosed in JP-A 2008-77361 (KOKAI) estimates the number of persons existing in a specific area by sensing the number of persons having passed the doorway. However, this estimation is based on the assumption that only one person passes through the doorway at one time, and this makes it difficult to accurately estimate the number of persons existing in each area. Also, the problem of cost arises because a person count sensor is additionally necessary.
Accordingly, an existent person count estimation apparatus is required to accurately estimate the number of existent persons. When the number of persons existing in each area is accurately estimated, it is possible to perform device control corresponding to the number of persons existing in each area, for example, control on/off of an illumination lamp or the operation mode of an air conditioner, thereby reducing unnecessary energy consumption.